The magnetic transducers and converters provide non-contact detection and measurement, supreme quality specifications, ability to operate in heavy and hazardous environments and others.
Hall effect devices are well known among the magnetic measuring devices. These devices basically are discrete elements (on-off switches). Their operating principle is based on appearance of voltage between edges of semiconductor crystal when electric current, and magnetic field in the direction, perpendicular to a direction of the current, are applied to the crystal (P. Horowitz, W. Hill "The Art of Electronics", 14.05. Magnetic Field, page 607, Cambridge University Press, 1980). The main disadvantage of Hall effect devices is their low efficiency coefficient. To obtain relatively large electric voltage on the output of Hall effect transducer, magnetic fields of significant intensity should be applied.
Ferreeds are also well known. Converters with discrete operating principle are designed on the basis of these ferreeds: the constant magnetic field of the electromagnet controls the state of the electric contacts, compensating mechanical forces of their elasticity (Van Nostrand's Scientific Encyclopedia, section "Ferreed", page 1165, Van Nostrand Reinhold Company, 1983; and Engineers' Relay Handbook, section "Ferreed Relays", page 68, Hayden Book Company Inc., New York, 1969). The inertia, presence of contacts, relatively low sensitivity and dispersion of parameters are the main disadvantages of these converters.
The ferromagnetic sond-modulators with frequency doubling are also known to play a role in measurement converters. They can be used to measure the Earth's magnetic field, for geomagnetic prospecting of mineral resources, in remotely controlled magnetic compasses, in mine detectors, and other applications. Their operating principles are based on the appearance of ferromagnetic coupling between an input and an output windings placed in some specific manner. This coupling occurs due to the periodic change of differential magnetic permeability of the cores, only when constant external magnetic field is applied to it (Van Nostrand's Scientific Encyclopedia, Magnetometer (flux-gate), page 1808, Van Nostrand Reinhold Company, 1983). The design including the ferromagnetic sondes is relatively complicated, bulky and requires significant supplemental circuitry.
Magneto-resistive semiconductor elements are also well known. Their operating principle is based on change of electric resistance of the solid in a magnetic field (McGraw-Hill Concise Encyclopedia of Science & Technology, Magnetoresistance, page 1025, McGraw-Hill, Inc, 1984). Disadvantages of the transducers based of this principle include narrow dynamic range of the detected changes of the magnetic field.
There is another discrete operation device for a remote control which contains the source of external magnetic field, sensor and output device (Avtorskoe Svidetelstvo (Transl. from Russian: Inventor's Certificate) No. 132660, Klimovitsky A. M. and others, USSR, State Committee for Inventions and Discoveries). The operating principle of this device is the closest to the operating principle of the proposed magnetic converter. This device can be considered as a prototype of the proposed converter.
The proposed magnetic measuring converter allows to solve a number of problems. The most important of them are reflected in the purpose of invention described in the summary.